This application relates to certain improvements in light emitting panel assemblies including one or more panels made of woven optical fibers having a fiber optic light pipe connected to one or both ends for transmitting light to the panel from a remote light source. Light is caused to be emitted from the panel by disrupting the surface of the optical fibers in the panel area as by scratching or otherwise deforming as by bending the optical fibers at a plurality of discrete locations along their length such that the angle of bend approximately exceeds the angle of internal reflection. The percentage of light emitted from each bend is proportional to the bend radius and arc length. By controlling the weave spacing and pattern of the woven optical fibers, one can control the shape and radius of the bends at any location on a woven panel to thereby control the desired light output pattern from the panel.
A fiber optic light emitting panel generally of this type is disclosed in applicant's aforementioned copending U.S. application Ser. No. 171,844. Also, as further disclosed in such copending application, the optical fibers can be coated with a material having a refractive index that will cause a change in the attenuation of the optical fibers in the light emitting portion of the panel to increase the optical efficiency of the panel. The amount of attenuation can be varied by varying the index of refraction and thickness of the applied coating.
In applications where the coating is applied to the entire length of the fibers in the light emitting portion of the panel, or such light emitting portion is completely encapsulated in such a coating, attenuation changes will occur over the entire light emitting portion. In other applications where increased optical efficiency is desired, it would be desirable to cause attenuation changes only at selected areas of the panel from which light is normally emitted.